The long-term objective of obtaining both Category I and Category II funding as part of this grant application is to enhance the capacity of the AAFP National Research Network to conduct research of clinical importance in primary care settings, disseminate and translate research findings and new scientific knowledge into practice, and assess the changes in the processes and outcomes of primary care practice. Specific Aims for Category I Funding for Network Infrastructure Support: 1. To increase the representation of minority and underserved patient populations in Network patient populations and available to Network studies to a minimum of 40-50 percent by recruiting minority physicians and other physicians serving these patient populations; 2. To develop a web-based survey system that will enhance the Network's capabilities to rapidly collect and analyze study data and, 3. To develop a training curriculum and train all study coordinators working with physicians in the National Research Network. Specific Aims for Category II Funding for a pilot study: 1. To describe and estimate rates of Test Processing Errors detected in family practice offices by physicians and office staff during intensive one-week monitoring periods; 2. To investigate the causes and consequences of these errors and, 3. To generate hypotheses about interventions to avert laboratory and imaging processing errors in primary care practices, which we will test in subsequent studies.